Controlling device for fluid-compressors.



C. WAINWRIGHT. GONTROLLING DEVICE FOR FLUID COMPRESSORS.

APlLlCATION FILED JUNE12`,1912.

` Patented 00's. 6, 1914.

vsrArras PATENT onirica.

CONTBOLLING DE'VIQE FOR FLUID-COMPBESSORS.

Specication of Letters Patent.

Application led Iune12, 1912. Serial No. 703,245.

To all whom t may concern Be it known that I,- CHARLES WAIN- wRioH'r, a citizen of theUnited States, residing at Erie, in the county of Erieand State of Pennsylvania, haveinvented 'new and useful Improvements in Controllin Devices for Fluid-Compressors, of whic the following is a specification.

The general object of the invention is to effect automatically the stopping unloading of an electrically driven fluid compressor upon the attainment of a predetermined pressure in the receiver of the compressor, and to maintain the compressor unloaded until the receiver pressure has dropped to a predetermined point and the pump mechanism again operating at normal speed. And to this end the invention consists in a controlling device arranged to control the passa e of fluid to a fluid actuated switch whic controlsl the motor circuit, and the passage of Huid to fluid actuated mechanism arranged to operate on the intake of the pump mechanism. i

Other objects will appear and be better understood from that embodiment of the invention of which the following is a specification, reference being had to the accompanying drawings forming a part hereof and in Which:-

Figure 1 is a diagrammatic view of the invention. Fig. 2 is an end elevation or the cylinderof the pump mechanism partly in section and disclosing the fluid actuated mechanism for operating on` the intake of the cylinder. Fig. 3 is a sectional detail of the means for controlling the` aage of Huid to the circuit controlling .i evice and the mechanism for operating on the intake.

The compressor a may be of the single or multiple stage type, or double acting aS shown. It is to be understood that .this showing is merely conventional and is given simply to illustrate one `application of the invention. The cylinder 5 is suitably connectedwith the receiver ofthe compressor. This receiver herein shown is made up of the pipe 6 and container 7. T he pump mechanism which includes the piston, not shown, and its connection with the'crarik shaft 8, is operated b a suitable. electric motor, not s own. he motor circuit is controlled. by a suitable automatic switch, not shown, and the circuit 9 for controlling the switch, is in turn, controlled by a fluid operated controller or pilot switch 10. The

and the` element 10 may be of any preferred con# struction and its fluid pressure operated indicator hand 11 is arranged to control the circuit 9 by successively contacting with the contact points 12 and 13. i

A pipe connection 14 is established between the switch 10 and a controller 15, which is suitably connected, such as by a pipe 16, to any point in the receiver of the compressor such as the container 7. A pipe 17 conveys the fluid to the mechanism for controlling the intake of the pump mechanism by preference is connected with a reservoir 18, whose opposite ends are iped as shown at 19-19 to depending cy indrical projections 20-20 at the opposite end portions of the cylinder 5. The intake valves, one of which is shown in Fig. 2 and indicated by 21, are operated through the action of the piston, not sho-wn, but I reserve the right to employ, if so desired, intake valves which are mechanically or otherwise actuated. In each of the cylindrical extensions 20, is arranged a plunger.' One .of such plungers is shown in Fig. 2 and indicated by 22, and referring to the said Fig. 2 it Awill be observed that the plunger projects into the valve cage 23` and its upper end is normally spaced from the stem 24 of the valve 21. The plunger is so arranged with respect to the pipe 19, that theuid which passes through the said pipe and into the cylindrical extension 20, will lift the plunger 22 into contact with the valve stem 24 and thereby unseat the valve 21.

A check valve 25 is connected in the pipe 17 and prevents the return of fluid into the pipe connection 14, and a vent or choke 26 is arranged so as to form the exhaust of the reservoir 18.

In use the adjustment of the controller 15 is eil'ected by turning the plug 27 which regulates the tension of the sprin 28. With the spring adjusted so as to yiel onl under a certain pressure in the receiver of t e compressor, and the needle valve 29 carried by the plunger 30 closing the passage 31 to the pipe connection 14, the effect obtained upon the attainment of a pressure in the receiver 7 sutiicient to overcome the tension of the s ring 28 will be as follows :--First, the xiiid will lift the valve 29 and its plunger and pass into the pipe connection 14 and into the switch 10. Here the indicator 11 will be moved from the contact 12 to the contact 13 and thereby effect-the breaking or Patented oet. e, 1914.

soV

opening, through the automatic switch, not shown, of the motor circuit and the consequent stopping of the motor. From the pipe connection 14 `the fluid will pass through the check valve and into the reservoir 18 through the pipe 17. f From 'the reservoir the fluid will pass through the pipes 19-19 and operate to lift the intake valves through the plungers in the extensions 20-20. Thus it will be seen that substantially synchronously with the stopping of the motor, the unloading -ofA t-he cylinder 5 will be had, and these etfects will continue until the pressure in the receiver is so reduced as to admit of the spring 28 closing the valve 29. When this is brought about, the air entrapped in the pipe connection 14: will escape through the vent 32 and permit the return' of the indicator 11 to its normal position as shown in Fig. l whereuponthey motor circuit will be closed and the motor caused to operate.A At this time;

however, the air entrapped in the pipe 17 will be prevented bythe check valve'25, from returning or backing into the pipeJ 14, and

inasmuch as the volume of the reservoir 18 is relatively large as compared with the volume of the pipe connection 14, it will be manifest that the pressure in such reservoir will keep the plungers 22 raised and the inlet valves 21 open after the closing of the motor circuit by the switch y10 so that the cylinder will remainv unloaded when the motor and the pump mechanism begin to operate and will remain so unloaded until the motor and the said pump lmechanism are operatingat normal speed. When sufficient fluid is eX hausted through the vchoke 26 to admit of the descent ofl the pistons 22,- the pump mechanism will become active and compress into the receiver as before.

From theforegoing it will( be 'observed thatthe arrangement of parts is such as to render the construction extremely simple and elicient ,and usable with any type of electrically driven compressor equipped with any automatic self-starting and stopping device, and'regardless of the kind of current` used for the motor of such compressor.

from said valve, a doublefbranch pipe con-- nected to the said ppe,-one branch of which communicates with a fluid controlled switch whereby the motor circuit. is opened or closed, thecth'er branch leading through a suitable check valve and a vent, a4 reservoir disposed adjacent to the compression chamber and with which ythe last mentioned `branch'conne'cts at a point between its ends, `said reservoir-having a pipe leading from each end and communicating' with a fluid controlled valve provided in the ends of the compression chamber', said* valves v being adapted vfor being opened by the pressure of the uid inthe reservoirwhereby the compression chamber lLis "relieved of excessive pressure, simultaneously-with the opening of the switch', 'l y v In testimonywhereof alix my signature in presence'of two witnesses.

CHARLES WAINWRIGHT.

Witnesses:

CARLTON F. PLATZ,

Geo. H. FRANK; 

